1. Field of the Invention
The present invention relates to a structure of a liquid crystal display device using a method of injecting a liquid crystal material by a vacuum injection method and a dripping injection method into the liquid crystal display device sandwiched between opposing substrates. In addition, the present invention relates to a technique for increasing productivity of a liquid crystal display device, and in particular, the present invention relates to a separating method for a multiple panel.
2. Description of the Related Art
Advances in making recent liquid crystal display devices large in size have come about with their expanding use as display devices such as notebook computers and personal computer workstations.
A seal pattern used for bonding a pair of substrates having electrodes, at least one of which is transparent, has the greater portion of the seal pattern swept along the end face of a substrate, as shown in FIG. 1 and FIG. 2.
FIG. 1 shows an element substrate 101, an opposing substrate 102, a display pixel portion 105, a peripheral driver circuit 106, an external lead-out wiring portion 107, a peripheral seal portion 103 so as to surround the display pixel portion 105 and the peripheral driver circuit 106, an injection port 104, and a sealing resin 111.
FIG. 2 shows an element substrate 201, an opposing substrate 202, a display pixel portion 205, a peripheral driver circuit 206, an external lead-out wiring portion 207, a peripheral seal portion 203 so as to surround the display pixel portion 205 and the peripheral driver circuit 206, an injection port 204, and a sealing resin 211.
When performing liquid crystal injection to this type of conventional liquid crystal display device (this type of liquid crystal display device is hereafter generically referred to as a liquid crystal display device A), the liquid crystal material wraps around the outside of the seal pattern, and loss of liquid crystal material develops. Considering that the cost of a TN liquid crystal is several thousand yen per gram, and the cost of an anti-ferroelectric liquid crystal is several tens of thousand yen per gram, reducing the loss of the liquid crystal material in order to enlarge the liquid crystal panel size and to perform mass production is urgent.
Further, in order to remove liquid crystal material adhering to the liquid crystal display device, an excess of cleaning solvent is necessary, and this has problems in production. In particular, the removal of the liquid crystal material which permeates the narrow gap and wraps around the outside of the closed seal pattern, as with a liquid crystal display device using a ferroelectric liquid crystal or an anti-ferroelectric liquid crystal, is difficult, and therefore the wave motion of ultrasonic waves is employed. However, when irradiating ultrasonic waves, fatal faults such as spacers moving due to a reduction in package strength, and the gap between substrates becoming non-uniform, are brought about.
In addition, in order to realize a lowering of costs, it is necessary to increase the number of liquid crystal panels manufactured from a pair of substrates having electrodes, at least one of which is transparent, namely it is necessary to increase the number which can be removed. A region on the outside of a liquid crystal display device on a substrate having electrodes becomes narrow, and a region capable of forming a dummy seal pattern (indicating, throughout this specification, a seal pattern other than a seal pattern formed so as to surround a display pixel portion and a peripheral driver circuit in order to confine the liquid crystal) becomes narrow, and a goal of stopping seal pealing cannot be sufficiently achieved.
Furthermore, when the dummy seal is not applied sufficiently, a reverse break develops during a separating process during manufacturing, and this has problems such as inviting a reduction in throughput. (When scribing, a cut line is first formed as a separating portion, and by breaking the substrate on the opposite side as the abrasion is formed, the cut line becomes a deep groove, and a scribe line is formed. However, during breaking, the substrate opposite to the substrate on which the cut line has been put is overloaded, and sometimes this substrate breaks. This type of break is indicated by the term reverse break throughout this specification.)
In order to inject a highly viscous ferroelectric liquid crystal or anti-ferroelectric liquid crystal in a short period of time, a case of using a previously proposed liquid crystal display device having a seal pattern possessing a plurality of injection ports has problems such as inviting a reduction in reliability by such factors as resistance to moisture.